Method of sharpening profile-sharpened cutting blades

Abstract

A method of sharpening cutting blades of the type made from bar stock type material, the method comprising producing relief surfaces on the cutting profile surface. The method comprises forming first and second relief surfaces on the cutting profile surface. The first relief surface extends from a location inward of the cutting edge to the back face and is oriented at a first relief angle with respect to a side surface. The second relief surface extends from the cutting edge to the first relief surface and is oriented at a second relief angle with respect to the side surface with the second relief angle being smaller than the first relief angle.

What is claimed is: 
     
       1. A method of sharpening a cutting blade of the profile-sharpened type made from a length of bar stock, said cutting blade having a base portion and a cutting end with said cutting end having a front rake surface, a back face, a top surface, and opposed side surfaces, said cutting end further including a cutting profile surface extending between said front rake surface and said back face, the intersection of said front rake face and said cutting surface defining a cutting edge, said method comprising: forming first and second relief surfaces on said cutting profile surface by removing stock material from said cutting surface,   said first relief surface extending from a location inward of said cutting edge to said back face with said first relief surface being oriented at a first relief angle with respect to one of said opposed side surfaces,   said second relief surface extending from said cutting edge to said location inward of said cutting edge with said second relief surface being oriented at a second relief angle with respect to said one of said opposed side surfaces, said second relief angle being less than said first relief angle.   
     
     
       2. The method of claim 1 wherein said forming comprises grinding. 
     
     
       3. The method of claim 1 further including a finishing operation performed on said second relief surface to further enhance the surface characteristics thereof. 
     
     
       4. The method of claim 3 wherein said finishing operation comprises grinding. 
     
     
       5. The method of claim 1 wherein said cutting profile surface includes a protuberant portion adjacent said top surface and extending between said front rake surface and said back face, said first and second relief surfaces being formed on a profile surface of said protuberant portion. 
     
     
       6. The method of claim 1 wherein said cutting end further includes a slot extending in a lengthwise direction through said front rake face, said slot intersecting a clearance profile side with a secondary cutting edge being defined by the intersection of said slot and said clearance profile side. 
     
     
       7. A method of sharpening a profile-sharpened cutting blade of the type made from a length of bar stock, said cutting blade having a base portion and a cutting end with said cutting end having a front rake surface, a back face, a top surface, and opposed side surfaces, said cutting end further including a cutting profile surface extending between said front rake surface and said back face, the intersection of said front rake face and said cutting surface defining a cutting edge, said cutting surface further including a protuberant portion adjacent said top surface and extending from said front rake surface to said back face, said method comprising: forming a first relief surface on said cutting profile surface by grinding, said first relief surface extending from a location inward of said cutting edge to said back face with said first relief surface being oriented at a first relief angle with respect to one of said opposed side surfaces,   forming a second relief surface on said cutting profile surface by grinding, said second relief surface extending from said cutting edge to said location inward of said cutting edge with said second relief surface being oriented at a second relief angle with respect to said one of said opposed side surfaces, said second relief angle being less than said first relief angle.   
     
     
       8. The method of claim 7 wherein said cutting end further includes a slot extending in a lengthwise direction through said front rake face, said slot intersecting a clearance profile surface with a secondary cutting edge being defined by the intersection of said slot and said clearance profile surface. 
     
     
       9. The method of claim 7 wherein said second relief angle is about 0.5 degree to about 5.0 degrees less than said first relief angle. 
     
     
       10. The method of claim 7 wherein said second relief surface is of a width of about 0.025 inch to about 0.250 inch. 
     
     
       11. The method of claim 7 further including an additional grinding pass over said second relief surface to further enhance the surface characteristics thereof. 
     
     
       12. The method of claim 7 wherein said grinding is effected by a grinding wheel comprising an inner conical portion and an adjacent outer narrow substantially flat surface. 
     
     
       13. A profile-sharpened cutting blade for cutting gears and the like, said cutting blade being formed from a length of bar stock and comprising: a base portion and a cutting end with said cutting end having a front rake surface, a back face, a top surface, and opposed side surfaces, said cutting end further including a cutting profile surface extending between said front rake surface and said back face, the intersection of said front rake face and said cutting profile surface defining a cutting edge,   said cutting profile surface comprising first and second relief surfaces,   said first relief surface extending from a location inward of said cutting edge to said back face with said first relief surface being oriented at a first relief angle with respect to one of said opposed side surfaces,   said second relief surface extending from said cutting edge to said location inward of said cutting edge with said second relief surface being oriented at a second relief angle with respect to said one of said opposed side surfaces,   said second relief angle being less than said first relief angle.   
     
     
       14. The cutting blade of claim 13 wherein said cutting profile surface includes a protuberant portion adjacent said top surface and extending between said front rake surface and said back face, said first and second relief surfaces being located on a profile surface of said protuberant portion. 
     
     
       15. The cutting blade of claim 13 wherein said cutting end further includes a slot extending in a lengthwise direction through said front rake face, said slot intersecting a clearance profile side with a secondary cutting edge being defined by the intersection of said slot and said clearance profile side. 
     
     
       16. The cutting blade of claim 13 wherein said second relief angle is about 0.5 degree to about 5.0 degrees less than said first relief angle. 
     
     
       17. The cutting blade of claim 13 wherein said second relief surface is of a width of about 0.025 inch to about 0.250 inch.